Problem snoring in subjects is often caused by an obstruction to the free flow of air through the passages at the back of the mouth and/or nose. Recently, the adverse medical effects of snoring and its association with Obstructive Sleep Apnea (OSA) and Upper Airway Resistance Syndrome (UARS) have been recognized. Various methods have been used to alleviate snoring or OSA. Such techniques include, e.g., behavior modification, sleep positioning, assisted breathing devices, jaw adjustment techniques, and surgical procedures such as Uvulopalatopharyngoplasty (UPPP), and laser assisted Uvula Palatoplasty (LAUP), for example.
Subjects who are prescribed assisted breathing devices, e.g., CPAP devices or Bi-level devices, use these devices to aid their breathing during sleep. A nasal CPAP device may deliver air into the subject's airway through a specially designed nasal mask or pillows. The device may create a flow of air having sufficient pressure to keep the airway open when the subject inhales. A blower is often provided in these devices to produce the desired airflow. In order to operate at an acceptably low sound level, and to avoid disturbing the subject's sleep, a noise suppression device may be provided to dampen the noise generated by the blower. For example, in some current CPAP and Bi-level devices, about 40% of the volume of the device is comprised of acoustic foam and empty volume provided for acoustic dampening.
Subjects may use these devices every night to achieve satisfactory sleep patterns regardless of whether they are at home or traveling. Thus, subjects who travel are generally required to bring a portable device with them in order to continue breathing assistance. For such traveling subjects, the size of the device may be an important consideration (e.g., due to limited luggage space). To illustrate the size of an example portable CPAP device, the Puritan Bennett GK 420 CPAP, which is illustrated as device “P” in FIGS. 1 and 3, measures approximately 7.5″×5.5″×3″.